Description

UCC28780 is a high-frequency active-clamp flyback controller that enables high-density
AC-to-DC power supplies that comply with stringent global efficiency standards such as DoE Level VI
and EU CoC V5 Tier-2. User programmable advanced control law features allow performance to be
optimized for both Silicon (Si) and Gallium Nitride (GaN) power FETs. Direct operation with
switching devices that combine driver and GaN FETs is further enhanced with logic-level gate
signals and enable outputs.

Zero voltage switching (ZVS) is achieved over a wide operating range with advanced
auto-tuning techniques, adaptive dead-time optimization, and variable switching frequency control
law. Using adaptive multimode control that changes the operation based on input and output
conditions, UCC28780 enables high efficiency while mitigating audible noise. With a variable
switching frequency of up to 1 MHz and accurate programmable over-power protection, which provides
consistent power for thermal design across wide line range, the size of passive components can be
further reduced and enable high power density.

UCC28780 works with VDS-sensing synchronous rectifier controllers, such as
UCC24612, to achieve higher conversion efficiency and
very compact designs.

Hardware development

Description

The UCC28780EVM-002 demonstrates high-efficiency and high-density for a 45-W off-line adapter using the UCC28780 active-clamp flyback controller at high frequency nominal 300 kHz using GaN MOSFET Power ICs, NV6115 and NV6117. The EVM also uses the UCC24612 synchronous rectifier controller on (...)

Description

The UCC28780EVM-021 is a 45-W evaluation module (EVM) for evaluating an off-line active-clamp flyback adapter for notebook charging and other applications. The EVM meets CoC Tier 2 and DoE Level 6 efficiency requirements. It is intended for evaluation purposes and is not intended to be an end (...)

Reference designs

PMP21552 — This reference design is a low-cost, high-density USB adapter that uses the UCC28780 active-clamp flyback controller and UCC5304 isolated driver in a ZVS-flyback topology. The maximum power rating is 65 W at 20-V output but is adjustable for 20-V/15-V/9-V/5-V output voltage and 3 A. This (...)

PMP21479 — This reference design uses the UCC28780 active clamp flyback controller to generate a 20-V/15-V/9-V/5-V adjustable output voltage. The maximum power rating is 65 W at 20-V output and up to 3 A at all other output voltage settings. This design reaches a peak efficiency of over 93% using silicon FETs (...)

PMP30720 — This reference design uses the UCC28C42 boost controller and the UCC28780 active-clamp flyback controller to generate an isolated output of 24 V at 3.5 A over an ultra-wide input voltage range of 20 V to 375 V. The design also uses the UCC24612 synchronous rectifier controller on the secondary side (...)

PMP40328 — PMP40328 is a maximum 9V 5A reference design for high frequency and high density adapter applications. The solution implements a high efficiency active clamp flyback controller UCC28780 and secondary rectifier controller UCC24612-2. The efficiency is around 90% at full load. Integrated input (...)